--- Begin Forwarded Message ---
Date: Sat, 16 Sep 2000 11:41:37 +0100
From: Andrew Cook <[log in to unmask]>
Subject: Re: Cataloging maps with a bad scale bar <fwd>
Sender: Andrew Cook <[log in to unmask]>


     I was about to respond along the same lines as Nancy Kandoian when I
     when I saw her thoughtful modification.  The problem comes up
     sufficiently often in an archive collection with office enlargements
     (or reductions) of unpublished sketch maps first constructed at
     standard scales.

     I don't try to compute a false RF from unit data I know to be wrong,
     lest the act of computation should be mistaken by users to validate in
     some way the measured quantities.  I prefer this:

     'Scale given as 8 miles to 5.75 inches, but actually ca. 1:230,000'

     I'd be glad to know of others' reactions on a connected point.  When
     computing an RF from a scale bar, or estimating it from a measured
     distance on the map, should one ever go beyond two significant figures
     in the RF calculation, e.g. 1:7500 or 1:15,000,000?  Only if it's
     plain that the mapmaker's scale bar is intended to represent a known
     inch-to-mile scale would I presume to supply a more precise RF, e.g.

     Scale of 20 miles [= 5.3 inches (approximately 4 miles to 1 inch or
     1:253,440)].

     Andrew Cook

     Dr Andrew S Cook
     Map Archivist
     India Office Records
     The British Library
     96 Euston Road              Telephone +44 20 7412 7828
     London NW1 2DB               Fax +44 20 7412 7641/7858
     United Kingdom               E-mail: [log in to unmask]


     ______________________________ Forward Header ________________________
     Date: Wed, 13 Sep 2000 18:44:20 -0400
     From: nkandoian <[log in to unmask]>
     Subject: Re: Cataloging maps with a bad scale bar <fwd>
     Sender: nkandoian <[log in to unmask]>

     I once had the situation of a natural scale printed on a map being
     incorrect, and I handled it by quoting the scale as indicated on the
     map, following by the corrected scale in square brackets:  Scale
     1:13,000 [i.e. 1:130,000?].  (I used a question mark instead of "ca."
     because it seemed like 1:130,000 was correct and the map maker had
     just left out a zero.)

     In your situation, since you are converting to (approximating) a
     natural scale anyway, how about putting only the correct scale in the
     255, with "ca." and in square brackets, and then adding a 500 note
     something like "Scale bar incorrectly indicates a scale of ca. ..."?
     And there you could either put a natural scale based on the bar scale,
     or use the units of the bar scale and express them in inches or
     centimeters.

     Nancy Kandoian
     Map Division
     NYPL
     [log in to unmask]

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